OBJECTIVE Laparoscopic pyeloplasty is an accepted therapy for primary ureteropelvic junction obstruction (UPJO), however difficulty associated with intracorporeal suturing has limited widespread clinical application. We report our initial experience of laparoscopic pyeloplasty performed with the daVinci robotic system matched to procedures performed with standard laparoscopic techniques. METHODS From June 2001 until August 2001, six patients underwent definitive management of primary UPJO using the daVinci robotic system. In four patients an Anderson-Hynes pyeloplasty was performed, while in two patients Fengerplasty was performed. Using demographic and preoperative information, each patient in the daVinci-assisted group was matched to a corresponding patient with primary UPJO undergoing laparoscopic pyeloplasty with standard techniques between November 1999 and June 2001. Perioperative results and follow-up data were subsequently compared. RESULTS Treatment groups were identical with regard to surgical procedure, gender, and side of UPJO. The length of hospitalization was 4 days for all patients, regardless of treatment group. Estimated blood loss was <50 cc in all cases. For Anderson-Hynes pyeloplasty, the mean overall operative and suturing times were 140 and 70 min using the daVinci system and 235 and 120 min using standard techniques, respectively. For the Fengerplasty, the mean overall operative and suturing times were 78 and 13 minutes using the daVinci system and 100 and 28 minutes using standard techniques, respectively. No complications were observed and there were no open conversions. CONCLUSIONS Anderson-Hynes pyeloplasty and Fengerplasty are feasible using either conventional laparoscopic techniques or the daVinci robotic system. In this initial pilot study, procedures performed with the daVinci robotic system resulted in overall decreased operative time, however factors responsible for the decreased operative time remain to be defined. Long-term prospective follow-up of procedures performed with or without the daVinci robotic system for surgeons with limited experience in laparoscopic management of UPJO is warranted to delineate the true efficacy of the device.